cmecde 564

 

89Neurology

Station 34

Sensory system of the upper limbs examination

Before starting

• Introduce yourself to the patient.

• Confirm his name and date of birth.

• Explain the examination and obtain his consent.

• Position him so that he is comfortably seated and ask him to expose his arms and to position

them so that the palms are facing towards you.

• Ask if he is currently experiencing any pain.

The examination

To examine the sensory system, test light touch, pain, vibration sense, and proprioception.

Do not forget to inspect the arms before you start. In particular, look for muscle wasting,

fasciculation, scars and other obvious signs.

• Light touch (not light rub or stroke). Ask the patient to close his eyes and to say ‘yes’ each time he

is touched with a wisp of cotton wool. Apply the cotton wool to his sternum as a test. Then apply

it to each of the dermatomes of the arm, moving from the hand and up along the arm. Remember

to compare both sides against each other, asking, “Does it feel the same on both sides?”.

• Pain. Ask the patient to close his eyes and apply a sharp object – ideally a neurological pin – to

the sternum and then to each of the dermatomes of the arm, as above. Compare both sides

against each other. If there is any loss of or difference in sensation, map out the area affected.

Figure 25. Dermatomes of the arm.

C4

C5

C5

POSTERIOR

ASPECT

ANTERIOR

ASPECT

C6

C8

C7

C4

C6

C7 C8

T3

T2

T1

T1

T3

T2

Clinical Skills for OSCEs

90 Station 34 Sensory system of the upper limbs examination

• Vibration. Ask the patient to close his eyes and apply a vibrating 128 Hz tuning fork (not the

smaller 512 Hz tuning fork used in hearing tests) to the sternum and then over the bony prominences of the arm, starting with the interphalangeal joint of the thumb and moving up to the

wrist and then the elbow (only if not felt more distally). Compare both sides against each other,

asking the patient to tell you when he feels the vibration stop (you can hasten this by touching

the tuning fork).

• Proprioception. Ensure that the patient does not suffer from arthritis or some other painful condition of the hand. Ask him to close his eyes. Hold the distal interphalangeal joint of his index

finger between the thumb and index finger of one hand. With the other hand, move the distal

phalanx up and down at the joint, asking him to identify the direction of each movement. Hold

the joint and phalanx from the sides, i.e. from their lateral and medial aspects. Tell the patient

something like, “I’m going to move your finger up and down. Is this up or down?” “What about this?

And that?” Again, compare both sides.

After the examination

• Thank the patient.

• Ensure that he is comfortable.

• Ask to carry out a full neurological examination.

• Summarise your findings and offer a differential diagnosis.

Conditions most likely to come up in a sensory system of the upper limbs examination station

Mononeuropathy:

• lesion affecting a single nerve, e.g. ulnar, median, or radial nerve (see Station 33).

Polyneuropathy:

• lesion affecting multiple nerves in a glove and stocking distribution, such as in diabetic

neuropathy.

Radiculopathy:

• lesion affecting a single root nerve, e.g. C6.

Brown–Séquard syndrome:

• numbness to touch and vibration and loss of proprioception (and weakness) on same side of

the lesion, and loss of pain and temperature sensation on the opposite side.

• caused by lateral hemisection or injury of the spinal cord.

Syringomyelia:

• loss of pain and temperature sensation but not of other sensory modalities.

91Neurology

Station 35

Motor system of the lower limbs examination

Before starting

• Introduce yourself to the patient.

• Confirm his name and date of birth.

• Explain the examination and obtain his consent.

• Position him and ask him to expose his legs.

• Ask if he is currently experiencing any pain.

The examination

Inspection

• Look for deformities of the foot.

• Look for abnormal posturing.

• Look for fasciculation.

• Assess the muscles of the legs for size, shape, and symmetry. You can also measure the circumference of the quadriceps or calves.

Tone

• Ensure that the patient is not in any pain.

• Ask the patient to relax the muscles in his legs.

• Test the tone in the legs by rolling the leg on the bed, by flexing and extending the knee, and/

or by abruptly lifting the leg at the knee.

Power

• Test muscle strength for hip flexion, extension, abduction and adduction, knee flexion and extension, plantar flexion and dorsiflexion of the foot and big toe, and inversion and eversion of

the forefoot. Compare muscle strength on both sides, and grade it on the MRC scale for muscle

strength:

0 No movement.

1 Feeble contractions.

2 Movement, but not against gravity.

3 Movement against gravity, but not against resistance.

4 Movement against resistance, but not to full strength.

5 Full strength.

Table 15. Important root values in the lower limb – muscle strength

• Hip flexion (femoral nerve and iliopsoas muscle) L1, L2

• Hip extension (inferior gluteal nerve and gluteus maximus muscle) S1

• Hip adduction (obturator nerve and adductor muscles) L2

• Knee flexion (sciatic nerve and hamstrings) L5, S1

• Knee extension (femoral nerve and quadriceps) L3, L4

• Foot dorsiflexion (deep peroneal nerve and tibialis anterior muscle) L4, L5

• Foot plantar flexion (tibial nerve and gastrocnemius muscle) S1

• Big toe dorsiflexion (deep peroneal nerve and extensor hallucis longus) L5

Clinical Skills for OSCEs

92 Station 35 Motor system of the lower limbs examination

Reflexes

• Test the knee jerk and ankle jerk with a tendon hammer (see Figure 26). Test the knee jerk by

raising and supporting the knee with one arm and striking the patellar tendon with the other.

To test the ankle jerk, abduct and externally rotate the hip and flex the knee and ankle. Then

strike at the Achilles’ tendon. Compare both sides. If a lower limb reflex cannot be elicited, ask

the patient to hook flexed fingers and pull apart while you re-test.

Figure 26. Testing the knee (A) and

ankle (B) reflexes.

• Test for clonus by holding up the ankle and rapidly dorsiflexing the foot (2–3 beats is normal).

• Test for the Babinsky sign (extensor plantar reflex) by scraping the side of the foot with your

thumbnail or, ideally, with an orange stick. The sign is positive if there is extension of the big

toe at the MTP joint, so-called ‘upgoing plantars’.

Table 16. Important root values

in the lower limb – reflexes

Knee jerk L3, L4

Ankle jerk S1

(A)

(B)

Neurology

Station 35 Motor system of the lower limbs examination 93

Cerebellar signs

• Carry out the heel-to-shin test.

– lie the patient on a couch. Ask him to run the heel of one leg down the shin of the other,

and then to bring the heel back up to the knee and to start again. Ask him to repeat the test

with his other leg

Gait

• If he can, ask the patient to walk to the end of the room and to turn around and walk back. (See

Station 37: Gait, co-ordination, and cerebellar function examination.)

After the examination

• Thank the patient.

• Ensure that he is comfortable.

• Ask to carry out a full neurological examination.

• If appropriate, indicate that you would order some key investigations, e.g. CT, MRI, nerve conduction studies, electromyography, etc.

• Summarise your findings and offer a differential diagnosis.

[Note] An upper motor neuron lesion is suggested by spastic tone, reduced power, brisk reflexes, up-going plantars,

reduced co-ordination, and clonus. A lower motor neuron lesion is suggested by normal or reduced tone, reduced

power, reduced reflexes, down-going plantars, normal co-ordination, wasting, and fasciculations.

Figure 27. Testing for the Babinsky or extensor plantar sign.

Clinical Skills for OSCEs

94 Station 35 Motor system of the lower limbs examination

Conditions most likely to come up in a motor system of the lower limbs examination station

Mononeuropathy:

• lesion affecting a single nerve, most commonly the

common peroneal nerve (resulting in foot drop).

Polyneuropathy:

• lesion affecting multiple nerves in a glove and

stocking distribution as in diabetic neuropathy.

Radiculopathy:

• lesion affecting a single root nerve (see Table 16).

Hemiplegia/hemiparesis:

• paralysis or weakness on one side of the body

accompanied by decreased movement control,

spasticity, and hyperreflexia (upper motor neurone

syndrome).

Cauda equina lesion:

• signs include unilateral or bilateral lower

limb motor and/or sensory deficits.

• the ankle jerks are usually absent on both

sides.

• upper motor neurone signs such as

Babinsky sign and clonus are absent.

Myopathy:

• symmetrical weakness predominantly

affecting proximal muscle groups.

• in contrast to neuropathy, in myopathy

muscle atrophy and hyporeflexia occur

very late.

95Neurology

Station 36

Sensory system of the lower limbs examination

Before starting

• Introduce yourself to the patient.

• Confirm his name and date of birth.

• Explain the examination and ask for his permission to carry it out.

• Position him on a couch and ask him to expose his legs.

• Ask if he is currently experiencing any pain.

The examination

To examine the sensory system, test light touch, pain, vibration sense, and proprioception.

• Do not forget to inspect the legs before you start. In particular, look for muscle wasting, fasciculation, scars, and any other obvious signs.

• Light touch (not light rub). Ask the patient to close his eyes and to say ‘yes’ each time he is

touched with a wisp of cotton wool. Apply the cotton wool to his sternum as a test. Then apply

it to each of the dermatomes of the leg, moving from the foot and up along the leg. Remember

to compare both sides against each other, asking, “Does it feel the same on both sides?”.

• Pain. Ask the patient to close his eyes and apply a sharp object – ideally a neurological pin – to

the sternum and then to each of the dermatomes of the leg, as above. Compare both sides

against each other. If there is any loss of or difference in sensation, map out the area affected.

• Vibration. Ask the patient to close his eyes and apply a vibrating 128 Hz tuning fork (not the

smaller 512 Hz tuning fork used in hearing tests) to the sternum and then over the bony prominences of the leg, starting with the interphalangeal joint of the big toe (test more proximally

only if not felt distally). Compare both sides against each other, asking the patient to tell you

when he feels the vibration stop (you can hasten this by touching the tuning fork).

L3

POSTERIOR

ASPECT

ANTERIOR

S1 ASPECT

L3

L4

L5

L2

L2

L1

L3

S2

L5

L4

L5 S1

S3

Figure 28. Dermatomes of the leg.

Clinical Skills for OSCEs

96 Station 36 Sensory system of the lower limbs examination

• Proprioception. Ensure that the patient does not suffer from arthritis, gout, or some other painful condition of the foot. Ask him to close his eyes. Hold the interphalangeal joint of his big toe

between the thumb and index finger of one hand. With the other hand, move the distal phalanx

up and down at the joint, asking him to identify the direction of each movement. Hold the joint

and phalanx from the sides i.e. from their lateral and medial aspects. Tell the patient something

like, “I’m going to move your toe up and down. Is this up or down?” “What about this? And that?”

Again, compare both sides. If the patient is able to stand, you can also perform Romberg’s test

(see Station 37: Gait, co-ordination, and cerebellar function examination).

After the examination

• Thank the patient.

• Ensure that he is comfortable.

• Ask to carry out a full neurological examination.

• If appropriate, indicate that you would order some key investigations, e.g. CT, MRI, nerve conduction studies, electromyography, etc.

• Summarise your findings and offer a differential diagnosis.

Conditions most likely to come up in a sensory system of the lower limbs examination station

Mononeuropathy:

• lesion affecting a single nerve.

Polyneuropathy:

• lesion affecting multiple nerves as in alcoholic or diabetic neuropathy.

Radiculopathy:

• lesion affecting a single root nerve (see Figure 28).

Cauda equina lesion:

• signs include unilateral or bilateral lower limb motor and/or sensory deficits, including ‘saddle

anaesthesia’ (loss of sensation in the area of the buttocks and perineum).

Hemisensory loss:

• loss of sensation including light, pain, temperature, vibration, and proprioception on one side

of the body.

• normally accompanied by hemiplegia/hemiparesis with attendant spasticity and hyperreflexia (upper motor neurone syndrome).

Brown–Séquard syndrome:

• numbness to touch and vibration and loss of proprioception (and weakness) on same side of

the lesion, and loss of pain and temperature sensation on the opposite side.

• caused by lateral hemisection or injury of the spinal cord.

Posterior column disease:

• loss of proprioception and vibration but not of other sensory modaliti

Station 37

Gait, co-ordination, and cerebellar function

examination

Before starting

• Introduce yourself to the patient.

• Confirm his name and date of birth.

• Explain the examination and obtain his consent.

• Ask if he is currently experiencing any pain.

Examination of gait

• Inspection. Inspect the patient in the sitting position, noting any abnormalities of posture. Ask

him to stand up and ensure that he is steady on his feet. Truncal ataxis suggests a midline cerebellar lesion. Inspect posture from both front and side.

• Gait and arm swing. Ask him to walk to the end of the room and to turn around and walk back.

If he normally uses a stick or frame, he should not be prevented from doing so. Note the gait

and also the arm swing and any difficulty in standing or turning.

• Heel-to-toe test/tandem gait. Ask him to walk heel-to-toe, ‘as if on a tightrope’. Ataxia on a

narrow-based gait suggests a cerebellar or vestibular lesion.

• Romberg’s test. Ask him to stand unaided with his feet together and his arms by his sides.

Assess with his eyes open and then with his eyes closed. If he sways and threatens to lose his

balance when his eyes are closed, the test is said to be positive, indicating posterior column

disease.

You must be in a position to steady the patient should he threaten to fall.

Examination of co-ordination

• Resting tremor. Ask the patient to sit down, to rest his hands in his lap, and to close his eyes.

Resting tremor is a sign of Parkinson’s disease.

• Intention tremor. Ask the patient to do something, e.g. remove his watch or write a sentence.

• Muscle tone in the arms. Examine muscle tone in the elbow (flexion and extension) and wrist

(flexion and extension, abduction and adduction) joints. Compare both sides.

• Dysdiadochokinesis. Ask the patient to clap and then show him how to clap by alternating the

palmar and dorsal surfaces of one hand. Once he is able to do this, ask him to do it as fast as he

can. Ask him to repeat the test with his other hand.

• Finger-to-nose test. Place your index finger at about 2 feet from the patient’s face. Ask him to

touch the tip of his nose and then the tip of your finger with the tip of his index finger. Once he

is able to do this, ask him to do it as fast as he can. And remember that he has two hands! Look

for intention tremor and dysmetria (past-pointing), both signs of cerebellar disease.

• Fine finger movements. Ask the patient to oppose his thumb with each of his other fingers in

turn. Once he is able to do this, ask him to do it as fast as he can. Again, remember that he has

two hands.

• Muscle tone in the legs. Ask the patient to lie down on a couch and, if possible, to relax the

muscles in his legs. Test the tone in his legs by rolling the leg on the bed, by flexing and extending the knee, and/or by abruptly lifting the leg at the knee.

• Heel-to-shin test. Ask the patient to run the heel of one leg down the shin of the other, and

then to bring the heel back up to the knee and to start again. Ask him to repeat the test with

his other leg.

Clinical Skills for OSCEs

98 Station 37 Gait, co-ordination, and cerebellar function examination

Assessment of cerebellar function

• If you are specifically asked to assess cerebellar function, carry out the above plus test

eye movements (nystagmus) and ask the patient to say ‘baby hippopotamus’ (slurred/

staccato speech). If you are then asked to list cerebellar signs, remember the mnemonic

DANISH:

– Dysdiadochokinesis and dysmetria (finger overshoot)

– Ataxia

– Nystagmus – test eye movements

– Intention tremor

– Slurred/staccato speech – ask the patient to say ‘baby hippopotamus’ or ‘British constitution’

– Hypotonia/hyporeflexia

After the examination

• Ask the patient if he has any questions or concerns.

• Thank the patient.

• Ensure that he is comfortable.

• Ask to carry out a full neurological examination.

• Summarise your findings and offer a differential diagnosis.

Conditions most likely to come up in a gait, co-ordination, and cerebellar function examination

station

Hemiplegic gait:

• the pelvis tilts upwards, the hip is abducted, and the leg is swung forwards in a semi-circular

movement.

• the leg is stiff and extended but the arm may be held in flexion and adduction with minimal

swing.

Scissor gait:

• a spastic gait seen in cerebral palsy and resulting from muscle contractures.

• the hips, knees, and ankles are flexed, producing a crouching and tiptoeing appearance.

• in addition, the hips are adducted and internally rotated, such that the knees cross or hit each

other in a scissor-like movement.

Festinating gait:

• seen in Parkinson’s disease.

• short shuffling steps with stiff arms and legs and stooped posture; difficulty starting and

turning.

Ataxic gait:

• seen in spinal and cerebellar lesions and in alcohol intoxication.

• unsteady, broad-based gait with a lurching quality.

Neuropathic gait:

• seen in peripheral neuropathies.

• weak foot dorsiflexors result in a high-stepping gait with foot-slapping; the high-stepping is

an attempt to prevent the foot from dragging and being injured; also called ‘high-stepping

gait’ or ‘foot-slapping gait’.

Neurology

Station 37 Gait, co-ordination, and cerebellar function examination 99

Trendelenburg gait:

• seen in weakness of the hip abductors or in an inability or reluctance to abduct the hip, e.g.

due to a fractured neck of femur or to arthritic pain.

• the pelvis tilts to the unaffected side in the stance phase; as a result, the trunk lurches to the

affected side in an attempt to maintain a level pelvis.

• bilateral Trendelenburg results in a typical waddling gait.

Antalgic gait:

• seen in arthritis and trauma.

• avoidance of motions that trigger pain.

• often quick, short, and light footsteps.

• not to be confused with a Trendelenburg gait.

Myopathic gait:

• in muscular diseases the proximal pelvic girdle muscles are most affected, such that the

patient is unable to stabilise the pelvis in the stance phase.

• the pelvis drops to the side of the leg being raised, and this results in a broad-based, waddling

gait.

Clinical Skills for OSCEs

100 Station 38

Speech assessment

The patient is likely to find the assessment difficult and distressing, so remember to be especially

empathetic. In particular, do not rush the examination or keep on interrupting the patient, but move

at a pace that feels comfortable for him.

Table 17. Definitions

Dysphonia Motor impairment of ability to vocalise speech

Dysarthria Motor impairment of ability to articulate speech

Dysphasia Cognitive impairment of ability to comprehend or express language

Aphasia Complete inability to comprehend or express language

Note: Expressive dysphasia (Broca’s area, in the inferolateral dominant frontal lobe) and receptive

dysphasia (Wernicke’s area, in the posterior superior dominant temporal lobe) often co-exist.

Before starting

• Introduce yourself to the patient.

• Confirm his name and date of birth.

• Explain the assessment and obtain his consent.

• Check that he speaks English and that he can hear you.

• Ask him to try to describe his current problems.

The assessment

Orientation in time and place

Time

Name: (year) (season) (month) (date) (day)

Place

Name: (country) (county/region) (town) (hospital) (floor)

Dysphasia

Expressive

Assess whether the patient has difficulty in finding the right words whilst in conversation with you.

You could ask directly, “It seems like you know what you want to say but you’re struggling to get the

words out. Am I right?”

Nominal

Nominal dysphasia is a common form of expressive dysphasia. Ask the patient to name some common

objects such as a watch, pen, or badge; then to name the components of some of these objects, e.g.

hour hand, winder, strap, picture. If he is unable to name the object, ask him what it does: a correct

answer can help to distinguish nominal from receptive dysphasia.

Neurology

Station 38 Speech assessment 101

Receptive

Assess whether the patient has difficulty understanding you by asking him to carry out some simple

instructions such as ‘shut your eyes’, ‘touch your nose’, and ‘point to the door’. If appropriate, try out

a more complex three-stage command, for example, “Using your left hand, touch your nose and then

touch my finger.”

Conductive

Conductive aphasia is the inability to repeat words or phrases despite intact understanding. Ask the

patient to repeat, “No ifs, ands or buts.”

Dysarthria

Ask the patient to repeat some of the following: ‘British constitution’, ‘West Register Street’, ‘Baby

hippopotamus’, ‘Biblical criticism’, ‘Artillery’.

Assess the structures involved in phonation and articulation by asking the patient to repeat:

• ‘Me, me, me’ Lips.

• ‘La, la, la’ Tongue.

• ‘Ah’ Palate, larynx, and expiratory muscles.

Dysphonia

• Make a note of the patient’s volume of speech, which may be low if there is weakness of the

vocal cords or respiratory muscles. Ask him to cough, and look out for ‘bovine’ cough, which

would suggest a lesion of cranial nerve X impairing the closure of the vocal cords.

Dyslexia

• Correct the patient’s vision and ask him to read a short paragraph from a newspaper or magazine, and bear in mind that not all people who can’t read are dyslexic!

Dyscalculia

• Ask the patient to carry out simple sums and subtractions.

Dysgraphia

• Ask the patient to write a sentence.

After the assessment

• Ask the patient if he has any questions or concerns.

• Thank him.

• Summarise your findings, offer a differential diagnosis, and state the probable area of the lesion.

• Suggest a plan for further investigations and management, for example, mental state examination, full neurological examination, and speech and language therapy assessment (including an

assessment of swallowing).

cmecde 5558

 

81Neurology

Station 32

Cranial nerve examination

Specifications: You may be asked to limit your examination to certain cranial nerves only, e.g. I–VI,

VII–XII.

Before starting

• Introduce yourself to the patient.

• Confirm his name and date of birth.

• Explain the examination and obtain his consent.

• Ensure that he is comfortable.

The examination

The olfactory nerve (CN I)

• Ask the patient if he has noticed a change in his sense of smell or taste. If he has, indicate that

you would perform an olfactory examination by asking him to smell different scents, such as

mint or coffee. Otherwise, the olfactory nerve is not formally tested.

The optic nerve (CN II)

(See Station 51: Vision and the eye examination for more details.)

• Ask the patient whether he wears glasses. If he does, ask him to put them on.

• Ask about any changes in vision and the time frame over which they have occurred. Use the

mnemonic AFRO C (Acuity, Fields, Reflexes, Ophthalmoscopy/Fundoscopy, and Colour vision)

to guide you through the following steps.

• Acuity: Use a Snellen chart from a distance of 6 metres and test near vision by asking the patient

to read test types (or a page in a book).

• Fields: Sit directly opposite the patient, at the same level as him. Ask him to look straight at

you and to cover his right eye with his right hand. Cover your left eye with your left hand, and

test the visual field of his left eye with your right hand. Bring a wiggly finger into the upper left

quadrant, asking the patient to say when he sees the finger. Repeat for the lower left quadrant.

Then swap hands and test the upper and lower right quadrants. Now ask the patient to cover

his left eye with his left hand. Cover your right eye with your right hand and test the visual field

of his right eye with your left hand. Bring a wiggly finger into the upper right quadrant, asking

the patient to say when he sees the finger. Repeat for the lower right quadrant. Then swap

hands and test the upper and lower left quadrants.

• Indicate that you could use a red hat pin to uncover the blind spot and the presence of a central

scotoma.

• Reflexes: See under CN III, IV and VI testing.

• Indicate that you could examine the eyes by direct ophthalmoscopy/fundoscopy.

• Indicate that you could test red/green colour vision with Ishihara plates.

Clinical Skills for OSCEs

82 Station 32 Cranial nerve examination

Figure 22. Visual field defects and their origins.

The oculomotor, trochlear, and abducens nerves (CN III, IV, and VI)

(See Station 51: Vision and the eye examination for more details.)

• Inspect the eyes, paying particular attention to the size and symmetry of the pupils, and excluding a visible ptosis (Horner’s syndrome) or squint.

• Test the direct and consensual pupillary light reflexes. Explain that you are going to shine a

bright light into the patient’s eye and that this may feel uncomfortable. Bring the light in onto

his left eye and look for pupil constriction. Bring the light in onto his left eye once again, but

this time look for pupil constriction in his right eye (consensual reflex). Repeat for the right eye.

• Perform the swinging flashlight test to detect a relative afferent pupillary defect. Swing the light

from one eye to another and look for sustained pupil constriction in both eyes. Intermittent

pupil constriction in one eye (Marcus Gunn pupil) suggests a lesion of the optic nerve anterior

to the optic chiasm.

• Perform the cover test. Ask the patient to fixate on a point and cover one eye. Observe the

movement of the uncovered eye. Repeat the test for the other eye.

• Examine eye movements. Ask the patient to keep his head still and to follow your finger with

his eyes. Ask him to report any pain or double vision at any point. Draw an ‘H’ shape with your

finger. Observe for nystagmus at the extremes of gaze.

• Test the accommodation reflex. Ask the patient to follow your finger in to his nose. As the eyes

converge, the pupils should constrict.

Optic

radiation

Lateral

geniculate

body

Optic

tract

Optic

chiasm

Left Right

Left eye

 Loss of vision

1

2

3

4

5

6

Right eye

Optic

nerve

5

6

3

4

2

1

Neurology

Station 32 Cranial nerve examination 83

The trigeminal nerve (CN V)

Sensory part

• Using cotton wool, test light touch in the three branches of the trigeminal nerve. Compare

both sides.

• Indicate that you could test the corneal reflex, but that this is likely to cause the patient some

discomfort.

Motor part

• Test the muscles of mastication (the temporalis, masseter, and pterygoid muscles) by asking

the patient to:

– clench his teeth (palpate his temporalis and masseter muscles bilaterally)

– open and close his mouth against resistance (place your fist under his chin)

• Indicate that you could test the jaw jerk. Ask the patient to let his mouth fall open slightly. Place

your fingers on the top of his mandible and tap them lightly with a tendon hammer.

The facial nerve (CN VII)

• Look for facial asymmetry. Note that the nasolabial folds and the angle of the mouth are especially indicative of facial asymmetry.

Sensory part

• Indicate that you could test the anterior two-thirds of the tongue for taste.

Motor part

• Test the muscles of facial expression by asking the patient to:

– lift his eyebrows as far as they will go

– close his eyes as tightly as possible (try to open them)

– blow out his cheeks

– purse his lips or whistle

– show his teeth

Ophthalmic

branch

Maxillary

branch

Mandibular

branch

Gasserian

ganglion

Trigeminal

nerve

Figure 23. The three branches

of the trigeminal nerve.

‘Trigeminal’ means ‘three twins’.

Clinical Skills for OSCEs

84 Station 32 Cranial nerve examination

The acoustic nerve (CN VIII)

(See Station 52: Hearing and the ear examination for more details.)

• Test hearing sensitivity in each ear by occluding one ear and rubbing your thumb and fingers

together in front of the other.

• Indicate that you could carry out the Rinne and Weber tests and examine the ears by auroscopy

(see Station 52).

The glossopharyngeal nerve (CN IX)

• Indicate that you could test the gag reflex by touching the tonsillar fossae on both sides with a

tongue depressor, but that this is likely to cause the patient some discomfort.

The vagus nerve (CN X)

• Ask the patient to phonate (say ‘aah’) and, aided by a pen torch, look for deviation of the uvula

to the opposite side of the lesion. Use a tongue depressor if necessary.

The hypoglossal nerve (CN XII)

• Aided by a pen torch, inspect the tongue for wasting and fasciculation.

• Ask the patient to stick out his tongue and look for deviation to the side of the lesion. Now ask

him to wiggle it from side to side.

The accessory nerve (CN XI)

• Look for wasting of the sternocleidomastoid and trapezius muscles.

• Ask the patient to:

– shrug his shoulders against resistance

– turn his head to either side against resistance

After the examination

• Thank the patient.

• Ensure that he is comfortable.

• If appropriate, state that you would order some key investigations, e.g. a CT or MRI.

• Summarise your findings and offer a differential diagnosis.

Conditions most likely to come up in a cranial nerve examination station

Third nerve palsy:

• the eye is depressed and abducted (down and out).

• elevation, adduction, and depression are limited, but abduction and intortion are normal.

• there is a ptosis (drooping of the upper eyelid).

• the pupil may be dilated and unreactive to light or accommodation.

Neurology

Station 32 Cranial nerve examination 85

Bell’s (facial nerve) palsy:

• facial drooping and paralysis on the affected half.

• if the forehead muscles are spared, it is a central rather than a peripheral palsy.

Horner’s syndrome:

• signs of Horner’s syndrome are ptosis, miosis, enophthalmos, and facial anhidrosis.

Cavernous sinus syndrome:

• the cavernous sinus contains the carotid artery and its sympathetic plexus, CN III, IV, and VI,

and the ophthalmic and maxillary branches of CN V.

• signs of a cavernous sinus lesion may include (generally unilateral) proptosis, chemosis,

ophthalmoplegia, and loss of sensation in the first and second divisions of the trigeminal

nerve.

Cerebellopontine angle syndrome:

• lesions in the area of the cerebellopontine angle can cause compression of CN V, VII, and VIII.

• signs may include palsies of CN V and VII, nystagmus, ipsilateral deafness, and ipsilateral

cerebellar signs.

Bulbar palsy:

• lower motor neurone lesion in the medulla oblongata leads to bilateral impairment of

function of CN IX–XII.

• signs include speech difficulties, dysphagia, wasting and fasciculation of the tongue, absent

palatal movements, absent gag reflex.

Pseudo-bulbar palsy:

• upper motor neurone lesion in the corticobulbar pathways in the pyramidal tract leads to

impairment of function of CN IX–XII and also CN V and VII.

• signs include speech difficulties, dysphagia, conical and spastic tongue, brisk jaw jerk,

emotional lability.

Clinical Skills for OSCEs

86 Station 33

Motor system of the upper limbs examination

Before starting

• Introduce yourself to the patient.

• Confirm his name and date of birth.

• Explain the examination and obtain his consent.

• Position him and ask him to expose his arms completely.

• Ask if he is currently experiencing any pain.

The examination

Inspection

• Look for abnormal posturing.

• Look for abnormal movements such as tremor, fasciculation, dystonia, athetosis.

• Assess the muscles of the hands, arms, and shoulder girdle for size, shape, and symmetry. You

can also measure the circumference of the arms.

Tone

• Ensure that the patient is not in any pain.

• Ask the patient to relax the muscles in his arms.

• Test the tone in the upper limbs by holding the patient’s hand and simultaneously pronating

and supinating and flexing and extending the forearm. If you suspect increased tone, ask the

patient to clench his teeth and re-test. Is the increased tone best described as spasticity (claspknife) or as rigidity (lead pipe)? Spasticity suggests a pyramidal lesion, rigidity suggests an

extra-pyramidal lesion.

Power

• Test muscle strength for shoulder abduction, elbow flexion and extension, wrist flexion and

extension, finger flexion, extension, abduction, and adduction, and thumb abduction and opposition. Compare muscle strength on both sides, and grade it on the MRC muscle strength scale:

0 No movement.

1 Feeble contractions.

2 Movement, but not against gravity.

3 Movement against gravity, but not against resistance.

4 Movement against resistance, but not to full strength.

5 Full strength.

Table 13. Important root values in the upper limb – muscle strength

• Shoulder abduction C5

• Elbow flexion C6

• Elbow extension C7

• Wrist extension C6, C7

• Wrist flexion C7, C8

• Finger extension C7 (radial nerve)

• Finger flexion C8

• Finger abduction/adduction T1 (ulnar nerve)

• Thumb abduction/opposition T1 (median nerve)

Neurology

Station 33 Motor system of the upper limbs examination 87

Reflexes

• Test biceps, supinator, and triceps reflexes with a tendon hammer (see Figure 24). Compare both

sides. If an upper limb reflex cannot be elicited, ask the patient to clench his teeth and re-test.

Table 14. Important root values

in the upper limb – reflexes

• Biceps C5, C6

• Supinator C6

• Triceps C7

Figure 24. Testing (A) biceps, (B) supinator, and (C) triceps

reflexes.

Cerebellar signs

• Test for intention tremor, dysynergia, and dysmetria (past-pointing) by asking the patient to

carry out the finger-to-nose test.

– place your index finger at about 2 feet from the patient’s face. Ask him to touch the tip of his

nose and then the tip of your finger with the tip of his index finger. Once he is able to do this,

ask him to do it as fast as he can. And remember that he has two hands!

• Then test for dysdiadochokinesis.

– ask the patient to clap and then show him how to clap by alternating the palmar and dorsal

surfaces of one hand. Once he is able to do this, ask him to do it as fast as he can. Ask him to

repeat the test with his other hand

(A)

(B)

(A)

(B)

(C)

Clinical Skills for OSCEs

88 Station 33 Motor system of the upper limbs examination

After the examination

• Thank the patient.

• Ensure that he is comfortable.

• Ask to carry out a full neurological examination.

• If appropriate, indicate that you would order some key investigations, e.g. CT, MRI, nerve conduction studies, electromyography, etc.

• Summarise your findings and offer a differential diagnosis.

Conditions most likely to come up in a motor system of the upper limbs examination station

Parkinson’s disease:

• motor signs include forward-flexed posture, mask-like facial expression, speech difficulties,

resting tremor, cogwheel rigidity, bradykinesia.

Cerebellar lesion:

• motor signs depend on the anatomy of the lesion, and may include nystagmus, slurred

or staccato speech, hypotonia, hyporeflexia, intention tremor, dysmetria, dysynergia,

dysdiadochokinesis, ataxia.

Ulnar nerve lesion:

• wasting, weakness, numbness, and tingling in the fifth finger and in the medial half of the

fourth finger.

• curling up of the fifth and fourth fingers (‘ulnar claw’) indicates that the nerve is severely

affected.

Median nerve lesion:

• a lesion at the level of the wrist produces wasting of the thenar muscles, weakness of

abduction and opposition of the thumb, and numbness over the palmar aspect of the thumb,

index finger, third finger, and lateral half of the fourth finger.

• a lesion at the level of the forearm produces additional weakness of flexion of the distal and

middle phalanges.

• a lesion at the   level of the elbow or above produces additional weakness of pronation of the

forearm and ulnar deviation of the wrist on wrist flexion.

Radial nerve lesion:

• a lesion at the level of the axilla or above produces weakness of elbow extension and flexion,

weakness of wrist and finger extension with attending wrist drop and finger drop, weakness of

thumb abduction and extension, and sensory loss over the dorsoradial aspect of the hand and

the dorsal aspect of the radial 3½ fingers (usually circumscribed to a small, triangular area over

the first dorsal web space).

• inferior lesions are likely to spare triceps (elbow extension), brachioradialis (elbow flexion),

and extensor carpi radialis longus (wrist extension and radial abduction, but this muscle is

only one of five wrist extensors).

Radiculopathy, affecting a single root nerve (see Table 14)

Hemiplegia/hemiparesis:

• paralysis or weakness on one side of the body accompanied by decreased movement control,

spasticity, and hyper-reflexia (upper motor neurone syndrome).

Myopathy:

• symmetrical weakness predominantly affecting proximal muscle groups.

• in contrast to neuropathy, in myopathy muscle atrophy and hyporeflexia occur very late.